A number of systems exist for transfer of a medium between two units offshore, where one unit is often a subsea installation, floating storage unit or a platform and the other unit a transport vessel.
Several of these systems have arrangements involving a transfer hose between the units, and when the hose is not in use, it is in a position where it is partially located on the seabed. Placing the hose in this position results in major wear and tear on parts of the hose, which means that the wear has to be monitored and parts of the hose have to be regularly replaced. These known loading systems are often also arranged so that the loading vessel can rotate freely and in an optimal manner relative to the weather when it is connected. In some systems this is accomplished by having a swivel system close to the connection point between the hose and the vessel. Alternatively, a submerged buoy may be provided which is housed in a receiving compartment in the vessel where the actual buoy or the end of the hose which is attached to the vessel comprises swivel devices, such as those described, for example, in U.S. Pat. No. 6,688,348. Another known system is to provide a swivel system at the anchoring point of the hose to the seabed. A system of this kind with swivels and their dynamic elements on the seabed leads to problems with regard to maintenance and repair. There are also systems which have permanently anchored towers with swivel devices arranged over the surface of the water. These are exposed to wind and weather and represent an obstacle to traffic on the surface of the water.
A transfer system is also known from GB 2273087, where a riser extends through an opening in a buoyancy element positioned below the surface. The transfer element is suspended in the buoyancy element in such a manner that the transfer element can form a J or an S-shape. We also refer to WO 2007/083238 which describes a loading system for loading from a subsea pipe system to a floating vessel.